Histochemical study of orcein-positive hepatocellular material in paraffin sections of liver biopsy samples in the course of various liver diseases.

A histochemical study was carried out on orcein-positive hepatocellular material in 111 cases, 27 of which were stained positively by orcein. Orcein-positive material was very frequently found in protracted viral hepatitis and in chronic active hepatitis, as well as in other liver diseases with or without cholestasis; it was absent in liver cirrhosis. In all the cases considered the orcein-positive material was mainly formed of proteins, rich in amino acids with sulfhydryl and disulphide radicals, tryptophan and, to a lesser extent, of NH2 alpha amino acids. The orcein-positive substance was apparently carbohydrate-free. The presence of copper was also confirmed.